Thread: Radius of SS rectangular 1 x 2 tubing edges ?

.065 and .120" wall thickness, 304. I need as sharp an edge as possible, which .065 probably has but rather have the strength of the .120". Only need 3 feet, so looking at McMaster mill finish

McMaster-Carr

Originally Posted by Milacron

.065 and .120" wall thickness, 304. I need as sharp an edge as possible, which .065 probably has but rather have the strength of the .120". Only need 3 feet, so looking at McMaster mill finish

McMaster-Carr

And you want to know what?

Tom

This mentions corner radius as 2x wall thickness for ERW tubing...

http://www.steeltubeinstitute.org/pd...n_brochure.pdf

In my shop I would tig-modify the wall if I needed to thicken it up for a tapped hole, etc....if you have an equivalent material round bar, simply drill a larger hole at location, install a short piece of solid round bar across the tube section, then plug weld it (essentially) on both sides. Find center with mill (if needed) and drill and tap. Round bar could be pretapped in the lathe if necessary.

Looks like it should have a max radius of .125" for .065 wall and .218" for .120 wall. I don't see the 1 x 2 listed with .065 wall here, but Online Metals has both wall thicknesses.

Rectangular Tubing Specifications - Provided by Penn Stainless Products

Originally Posted by matt_isserstedt

This mentions corner radius as 2x wall thickness for ERW tubing...

http://www.steeltubeinstitute.org/pd...n_brochure.pdf

In my shop I would tig-modify the wall if I needed to thicken it up for a tapped hole, etc....if you have an equivalent material round bar, simply drill a larger hole at location, install a short piece of solid round bar across the tube section, then plug weld it (essentially) on both sides. Find center with mill (if needed) and drill and tap. Round bar could be pretapped in the lathe if necessary.

Thanks Matt, very interesting. This sort of thing might even be in Machinery's Handbook...but since it's the sort of thing that definitely should be in Machinery's Handbook, I figure on that basis alone it probably isn't, so didn't bother to look

Note it's common for tubing over .065 wall to have three tight corners and one more rounded one; the last bend as it's closed up for seam welding. Thinner tubing usually has one odd corner, but it's usually not that much different.

Originally Posted by Dave W

Note it's common for tubing over .065 wall to have three tight corners and one more rounded one; the last bend as it's closed up for seam welding. Thinner tubing usually has one odd corner, but it's usually not that much different.

I never noticed that before...interesting.

It depends on the wall thickness but 2x2 .250 wall has two small , two larger radius's, like a D shape----------- If you have ever make SS frames for the food industry it becomes real obvious when rolling the tubing 45 degrees to make frames in order to eliminate flat surfaces. When you mitre the corners it shows up.

my opinion is it depends on how the tube is made and for what industry. In furniture grade induction welded tubing there is no standard corner radius, they are all more or less equal ( in my carbon steel experience ) and is totally customer specified. If this stuff is not made on a tube mill but basically broke 4 times it could be a different story, but if its run on a real tube mill I'd say it would be dumb to have different radii around the tube. If it did they were cheating the parent tube diameter to reduce material cost and not totally filling out the sizing rolls.